I suppose I need to update this thread.
I've put the new calipers from Raybestos, part numbers: FRC4124N and FRC4123N, which were NOT uncoated. They had some kind of shiny coating for rust prevention, so that's cool. However, the calipers didn't have clearance for the shims on the top of the pad on the piston side. A lot of them are attached by glue, so I just clipped the pieces that extended past the top.
I sanded the pads and the rotors to try to get a better break in. No real change however. The brakes seem to grab more when it's hotter.
I got some new return springs from a hardware kit that I bought locally from NAPA. I had a Carlson kit H7191 from rockauto that I'm replacing. That may have been it. The rear brakes don't grab as easy. The pads have a ways to go to clear through some of the glazing and really do some work.
I'll continue to drive it and see. If I get employed, may get the original combo/proportioning valve rebuilt.